The Gene Expression Profiling core will carry out studies of differences in gene expression in mouse tissues. This will primarily involve the use of cDNA or EST libraries arrayed on glass slides. These will be probed with RNA (reverse transcribed into fluorescently labeled cDNA) prepared from the relevant tissues (control condition and perturbed condition). These studies will employ a Genetic Microsystems model GMS 417 Arrayer, model GMS418 dual wavelength laser confocal Array Scanner and Imaging Research Array Vision software. Arrays will consist of difference libraries or mouse Unigene sets. These studies will aid in the identification of atherosclerosis susceptibility genes (Project 1) and in the discovery of novel genes involved in the macrophage response to atherosclerosis (Projects 2-4).